Last month, I did blog entry on the way hundreds of lucky US company bosses inflated their pay by as much as 10 per cent by secretly backdating share options, with the options being granted at the point of the month when the share price was at its lowest.

How did they do it? Look at the directors!

According to a new study Lucky Directors by the same authors, nine percent of 29,000 option grants to outside directors from 1996 to 2005 were granted on a day when the company stock price was at a monthly low. Let's be clear: the likelihood of this sort of luck happening in such big batches is close to statistically impossible.

Even more alarming is the suggestion that some directors are not only doing nothing to stop bad behavior by executives - they might even be colluding.

The study goes so far as to suggest that executives and directors just might be working hand in glove: "Directors' grant events were more likely to be lucky when executives and especially the CEO also received a grant on the same date. Grant events not coinciding with an award to executives were still more likely to be lucky when the CEO got a lucky grant in the current or preceding year."

Directors were more likely to engage in this sort of aiding and abetting behavior at companies where insiders were well-entrenched and where there were few independent directors.